Riken Corporation

Japan Science and Technology Agency

The Institute of Physical and Chemical Research

Akebono Research and Development Center Ltd.

Tadahisa Iwata

Yoshiharu Doi

Hideki Yamane

Toshihisa Tanaka

Satoshi Kusaka

An object of the present invention is to provide: a process for conveniently producing a fiber with high strength, regardless of molecular weight polymer composition, or the like of PHAs, which vary depending on origins such as a wild-type PHAs-producing microorganism product, a genetically modified strain product, and a chemical product; and the fiber with high strength produced through the process. The present invention provides: a process for producing a fiber, comprising: melt-extruding polyhydroxyalkanoic acid to form a melt-extruded fiber; rapidly quenching the melt-extruded fiber to the glass transition temperature of polyhydroxyalkanoic acid +15&#xb0; C. or less, and solidifying the fiber to form an amorphous fiber; forming a crystalline fiber by leaving the amorphous fiber to stand at the glass transition temperature +15&#xb0; C. or less; drawing the crystalline fiber; and further subjecting the crystalline fiber to stretch heat treatment.

High-strength fiber of biodegradable aliphatic polyester and process for producing the same

The present invention is a process for producing a fiber, comprising: melt-extruding polyhydroxyalkanoic acid; solidifying the polyhydroxyalkanoic acid by quenching it to its glass transition temperature +15&#xb0; C. or less, to form an amorphous fiber; cold-drawing the amorphous fiber at its glass transition temperature +20&#xb0; C. or less; and subjecting the fiber to heat treatment under tension. The present invention can provide: a process for producing a fiber with high strength, and the fiber produced through the process; and a process for producing a fiber with high strength and high modulus of elasticity and the fiber with high strength and high modulus of elasticity produced through the process, regardless of molecular weights of PHAs varying depending on origins such as a wild type PHAs-producing microorganism product, a genetically modified product, and a chemical product.

Polyhydroxyalkanoic acid fibers with high strength, fibers with high strength and high modulus of elasticity, and processes for producing the same

Poly(3-hydroxybutanoic acid) having a number average molecular weight of not less than 500,000 is oriented at a draw ratio of 2-fold or more to reproducibly obtain a film made of poly(3-hydroxybutanoic acid) having biodegradability and biocompatibility as well as sufficient strength and flexibility (for example, tensile strength of not less than 30 MPa and elongation to break of not less than 15%).

Poly(3-hydroxybutanoic acid) film

Growing community of inventors

Wako, Japan

Tadahisa Iwata